Does anyone have recommendations on how to clean the outside chambers of the sump? I have an Aqueon ProFlex sump, with a live rock/ algae refugium in the middle. My issue is that I have some sand sediment on both the intake chamber and the final chamber (with skimmer and return pump). I have tried to suck it out with the old water change siphon, but it isn't very successful. Does anyone have advice on how to get this surface dusting of sand sediment out?